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1.
Thermogravimetrical analysis has been used to study the kinetics of thermal deamination of bis(ethylenediamine)nickel(II)-containing aluminophosphate (Ni-CHA) which is a precursor of nickel(II)-containing chabazite-like AlPO4-34. The deamination occurs as a single-step kinetic process which is best described by the contracting cylinder model. The obtained activation energy of 200 kJ/mol is mainly a reflection of the strong Ni-N coordination bond. The thermal decomposition of Ni-CHA results in the deposition of crystalline NiO particles homogeneously dispersed in the AlPO4-34 lattice. Average particle size was found to be about 5 nm. The study confirms that the thermal decomposition of amine complexes of Ni(II) encapsulated inside the microporous aluminophosphate host can be a suitable method for obtaining fine nano-oxide particles.  相似文献   

2.
The reaction of α-MgCl2 with boiling ethyl acetate affords MgCI2(CH3COOC2H5)2· (CH3COOC2H5), which is obtained as crystals suitable for X-ray analysis only from the mother liquor. M=315.5, orthorhombic, space group P21221 (No. 18), a=25.077(3), b=8.616(1), c=7.345(1) Å, V=1587.0(3) Å3, Z=4, Dx=1.32 g cm−3,λ A(Mo Kα)=0.71069 Å, μ=4.17 cm−1, F(000)=664, T=298 K, observed reflections: 1667, R=0.059 and Rw=0.069. The structure is composed of polymeric chains of MgCl2(CH3COOC2H5)2 and the ethyl acetate molecules occupy a mutually trans position.  相似文献   

3.
Hydrothermal reactions of lead(II) acetate and HO2C(CH2)3N(CH2PO3H2)2 at 170 and 140 °C, respectively, resulted in two different lead diphosphonates, namely, Pb2[NH(CH2PO3)2] · 2H2O (1), in which the butyric acid moiety of the HO2C(CH2)3N(CH2PO3H2)2 has been cleaved and a novel layered compound, Pb3[HO2C(CH2)3NH(CH2PO3)2]2 · 2H2O (2). Their crystal structures have been determined by single crystal X-ray diffraction. In compound 1, the interconnection of the lead(II) ions by bridging amino-diphosphonate ligands leads to the formation of a 3D network. Compound 2 features an unusual triple-layer structure with the non-coordinated butyric acid moieties as pendant groups between the layers.  相似文献   

4.
A new ruthenium nitric oxide complex with the bidentate phosphine, 1,2-bis(diethylphosphino)ethane (depe), has been synthesized and characterized by UV-Vis, infrared, EPR, NMR, electrochemical techniques and X-ray structure determination. The electronic spectrum showed a typical band of dπ→pπ* charge-transfer (CT) transition, assigned to Ru(II)NO transition, and the vibrational spectrum exhibited a peak of nitrosyl ligand at (νNO=1851 cm−1). A model structure for this complex has been proposed based on 1H, 1H{31P}, 31P{1H}, 13C{1H}, COSY 1H1H{31P}, J-Resolved, HSQC, HMBC, HSQC 1H13C{31P} and 1H13C HSQC/1H1H TOCSY spectral data, and confirmed by X-ray diffraction. The nitrosonium character for the NO ligand become evident through both electron paramagnetic resonance and X-ray data (angle RuNO=177.4(3)°). The reversible monoeletronic process at E1/2=0.040 V versus SHE was assigned to the ligand NO+/NO redox couple. Under treatment with Cd(Hg) solutions containing the [Ru(NO)(depe)2Cl](PF6)2 yields a signal in the EPR spectrum (g=1.99 and g//=1.88) which fitted quite well with the simulated spectra of coordinated NO species.  相似文献   

5.
A zinc phosphate with the composition [NH3-CH2-CH(NH3)-CH3](ZnPO4)2, containing the doubly protonated 1,2-diaminopropane (abbr. HDAP), was synthesized by hydrothermal crystallization of zinc nitrate, phosphoric acid, 1,2-diaminopropane and trimethylenedipiperidine. The single crystal analysis shows a layered inorganic-organic structure built up of a sandwich-like motif of alternating inorganic layers and HDAP cations (trimethylenedipiperidine not being a constituent of the structure). The HDAP species are found to be disordered and serve as bridges between two adjacent inorganic layers which are separated by 3.95 Å. The bridging interaction occurs via a hydrogen-bonding network. The inorganic layer features a pattern of four-membered rings involving two ZnO4 and two PO4 tetrahedra connected by sharing O atoms. Thermal analysis shows that the compound is stable up to 370 °C and that the thermal decomposition of HDAP occurs in two steps between 370 and 460 °C, causing the collapse of the structure. The first decomposition step corresponds to ammonia removal which proceeds with a high activation energy (Ea = 282 kJ mol−1). The high Ea value is mainly attributed to strong electrostatic interactions between organic cations and anionic inorganic layers, the disruption of the interactions being the main reason for structural collapse after the HDAP removal.  相似文献   

6.
7.
Complexes of the type [Pt(amine)4]I2 were synthesized and characterized mainly by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. The compounds were prepared with different primary amines, but not with bulky amines, due to steric hindrance. In 195Pt NMR, the signals were observed between −2715 and −2769 ppm in D2O. The coupling constant 3J(195Pt-1H) for the MeNH2 complex is 42 Hz. In 13C NMR, the average values of the coupling constants 2J(195Pt-13C) and 3J(195Pt-13C) are 18 and 30 Hz, respectively. The crystal structure of [Pt(EtNH2)4]I2 was determined by X-ray diffraction methods. The Pt atom is located on an inversion center. The structure is stabilized by H-bonding between the amines and the iodide ions. The compound with n-BuNH2 was found by crystallographic methods to be [Pt(n-BuNH2)4]2I3(n-BuNHCOO). The crystal contains two independent [Pt(CH3NH2)4]2+ cations, three iodide ions and a carbamate ion formed from the reaction of butylamine with CO2 from the air. When the compound [Pt(CH3NH2)4]I2 was dissolved in acetone, crystals identified as trans-[Pt(CH3NH2)2(H3CNC(CH3)2)2]I2 were isolated and characterized by crystallographic methods. Two trans bonded MeNH2 ligands had reacted with acetone to produce the two N-bonded Schiff base Pt(II) compound.  相似文献   

8.
植物排放N2O和CH4的研究   总被引:1,自引:0,他引:1  
N2O和CH4是2种重要的温室气体, 但其排放源尚未得到充分鉴别。1990年和2006年先后报道植物能排放N2O和CH4, 并日益受到广泛的关注。然而, 迄今为止对植物排放这2种气体的研究均是分开单独进行的。该文以8种陆生草本植物为研究对象, 首次同步考察了新鲜离体植物地上部排放N2O和CH4的通量。研究结果表明: 8种植物均能排放这2种气体。其中, 黑麦草(Lolium perenne)、抱茎苦荬菜(Ixeridium sonchifolium)和菠菜(Spinacia oleracea)的CH4通量较高, 分别为165.38、 52.28和21.64 ngCH4·g–1dw·h–1; 抱茎苦荬菜、蒙古蒿(Artemisia mongolica)、大豆(Glycine max)和菠菜的N2O通量较高, 分别为7.19、6.92、5.44和4.05 ngN2O·g–1dw·h–1。研究结果不仅为植物本身既能排放N2O又能排放CH4在植物中可能具有普遍性提供了进一步的实验依据, 而且为深入研究其机理找到了几种适宜的植物种(如抱茎苦荬菜、菠菜)。  相似文献   

9.
A novel oligonucleotide analog has been prepared from ribonucleoside derived morpholine subunits linked by carbamate groups. Oxidative cleavage of the 2',3' vicinal diol of cytidine followed by reductive amination of the resulting dialdehyde afforded the morpholine subunit. Coupling of the subunits are through carbamate moieties and the oligomers were characterized by 1H NMR and FAB MS. Evidence for interaction of the hexamer 19 with p(dG6) was found, but an atypical interaction of 19 with a RNA target was observed.  相似文献   

10.
A seven-coordinate FeIII complex, [Fe(oda)(H2O)2(NO3)], was obtained after dissolving Fe(NO3)3 · 9H2O in an aqueous solution of oxydiacetic acid (H2oda) at room temperature. In the solid state, the FeIII center adopts a pentagonal bipyramid geometry with an {FeO7} core formed by a tridentate oda2− and a bidentate in the equatorial plane, and two axial water molecules. Magnetic measurements and EPR spectra revealed the presence of S = 5/2 FeIII centers with rhombic zero field splitting parameters (D = 0.81 cm−1, E/D = 0.33 ). Weak antiferromagnetic interactions with J ≈ −0.06 cm−1 operating between neighboring Fe ions connected through Fe-O-C-O?H-O-Fe paths are estimated using the molecular field approximation.  相似文献   

11.
Two new zincophosphites [C6H14N2]0.5[Zn(H2PO3)2] 1 and [C4H12N2]0.5[(CH3)2NH2][Zn2(HPO3)3] 2 have been solvothermally synthesized in mixed solvents of N,N-dimethylformamide (DMF) and 1,4-dioxane (DOA), respectively. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a neutral inorganic chain formed by ZnO4 and HPO2(OH) units. Interestingly, the left- and right-handed hydrogen-bonded helical chains are alternately formed via the hydrogen-bonds between two adjacent chains. Compound 2 exhibits a layer structure with 4- and 12-MRs formed by ZnO4 and HPO3 units, in which two kinds of organic amine molecules both act as countercations to compensate the overall negative electrostatic charge of the anionic network.  相似文献   

12.
The new tripodal phosphine CH3C{CH2P(m-CF3C6H4)2}3, CF3PPP, was prepared by reacting CH3C(CH2Br)3 with Li+P(m-CF3C6H4)2, the latter being best obtained by adding Li+NiPr2 to PH(m-CF3C6H4)2. The rhodium complexes [RhCl(CO)(CF3PPP)], [Rh(LL)(CF3PPP)](CF3SO3) (LL = 2 CO or NBD), [RhX3(CF3PPP)], [RhX(MeCN)3(CF3PPP)](CF3SO3)2 (X = H and Cl), [RhCl2(MeCN)(CF3PPP)](CF3SO3) and [Rh(MeCN)3(CF3PPP)](CF3SO3)3 were prepared and characterized. The X-ray crystal structure of [Rh(NBD)(CF3PPP)](CF3SO3) is reported. The lower oxygen sensitivity of the CF3PPP rhodium(I) complexes, relative to the corresponding species with the parent ligand CH3C(CH2PPh2)3, is attributed to the higher effective nuclear charge on the metal centers caused by the presence of the six CF3 substituents on the terdentate phosphine. A similar effect may be responsible for the easier hydrolysis of the CF3PPP-containing, cationic rhodium(III) complexes relative to the corresponding compounds of the parent ligand.  相似文献   

13.
小叶章生态系统根际土壤微生物及CO2、CH4、N2O动态   总被引:3,自引:0,他引:3  
徐小锋  宋长春  宋霞 《生态学报》2005,25(1):182-187
研究了培养 4 5 d的小叶章根际土壤微生物和二氧化碳 ,甲烷及氧化亚氮产生与消耗之间的关系。结果表明好氧微生物与厌氧微生物的空间分布与甲烷 ,二氧化碳及氧化亚氮的产生和氧化有着密切的关系。好氧微生物与甲烷产生呈负相关 ,与二氧化碳和氧化亚氮的产生呈正相关关系。厌氧微生物与甲烷的产生呈正相关 ,与二氧化碳和氧化亚氮的产生呈负相关关系  相似文献   

14.
生物炭与氮肥对旱作春玉米农田CO_2和CH_4排放特征的影响   总被引:1,自引:0,他引:1  
为了研究生物炭与氮肥对旱作春玉米农田CO_2和CH_4排放通量季节变化、累积排放总量及CO_2+CH_4排放强度的影响,试验设置C_0N_0(不加生物炭,不施氮肥)、C_0N_1(不加生物炭,施氮肥225kg·hm~(-2))和C_1N_1(添加生物炭50t·hm~(-2),施氮肥225kg·hm~(-2))3个处理,采用密闭式静态暗箱-气相色谱法对不同生物炭和氮肥输入旱作春玉米农田CO_2和CH_4排放通量进行连续观测,同时对影响通量变化的0~20cm土层温度和水分因子进行测定。结果表明:(1)试验期内不同处理春玉米农田均表现为CO_2累积通量的源,且CO_2排放通量均呈现一定的峰值变化规律。(2)C_1N_1处理减少了春玉米生长季农田CO_2排放通量和累积排放总量,在试验的2个生长季内农田CO_2平均排放通量和累积排放总量各处理均表现为C_0N_0C_0N_1C_1N_1,且C_1N_1处理降低显著。(3)土壤CO_2排放通量与土壤温度变化呈显著正相关关系,可用指数方程和二次方程较好拟合二者关系,且与10cm土层温度的相关性优于0cm土层温度,但土壤CO_2排放通量与土壤含水量呈负相关关系。(4)试验各处理农田土壤CH_4排放通量在-16.08~-73.96μg·m~(-2)·h~(-1)之间,表现为大气CH_4的净吸收库;C_1N_1处理增加了土壤CH_4排放通量和累积排放总量,但作用效果的显著性受年际环境因子的影响;农田土壤CH_4排放通量与土壤含水量呈显著正相关关系,与土壤温度呈显著负相关关系。研究发现,添加生物炭和施氮减少了旱作农田春玉米生长季CO_2排放通量和累积排放总量,增加了CH_4排放通量和累积排放总量,总体上显著增加了春玉米产量,显著减少农田CO_2+CH_4排放强度。  相似文献   

15.
The aim of this investigation was to test the hypothesis that elevation of intracellular pH would inhibit iron uptake by reticulocytes. The experiments were performed with rabbit reticulocytes and iron bound to rabbit transferrin. Incubation of the cells with NH4Cl, (NH4)2CO3, CH3NH2 and (CH3)2NH was used in an attempt to increase intracellular pH. These substances were all found to inhibit iron uptake by reticulocytes. The mechanism of action of NH4Cl and CH3NH2 was investigated in detail. Similar results were found with both reagents. They inhibited iron uptake in a concentration-dependent manner, but produced a small increase in the cellular uptake of transferrin. The onset of action was rapid and the effect was reversible. There was no decrease in the number of transferrin-binding sites per cell and their apparent affinity for transferrin increased slightly, while the efficiency of iron removal from transferrin per binding site diminished greatly. The rate of transferrin release from reticulocytes was unaffected. NH4Cl did not affect the rate of iron release from transferrin in a cell-free system. Incubation of reticulocytes with 10 mM NH4Cl or CH3NH2 was found to produce an increase in intracellular pH of 0.05—0.15 pH units. The intracellular pH determined by used of the weak acid 5,5-dimethyl-oxazolidine-2,4-dione was significantly higher than that obtained with the weak base (CH3)2NH. By transmission electron microscopy it was shown that reticulocytes treated with NH4Cl or CH3NH2 have enlarged intracellular vesicles. The results are considered to support the hypothesis that iron release from transferrin in reticulocytes occurs as a result of protonation of the transferrin within intracellular vesicles. According to this hypothesis, weak bases such as NH3 and CH3NH2 inhibit iron release by neutralizing H+ within the vesicles.  相似文献   

16.
The organotin complex [Ph3SnS(CH2)3SSnPh3] (1) was synthesized by PdCl2 catalyzed reaction between Ph3SnCl and disodium-1,3-propanedithiolate which in turn was prepared from 1,2-propanedithiol and sodium in refluxing THF. Reaction of 1 with Ru3(CO)12 in refluxing THF affords the mononuclear complex trans-[Ru(CO)4(SnPh3)2] (2) and the dinuclear complex [Ru2(CO)6(μ-κ2-SCH2CH2CH2S)] (3) in 20 and 11% yields, respectively, formed by cleavage of Sn-S bond of the ligand and Ru-Ru bonds of the cluster. Treatment of pymSSnPPh3 (pymS = pyrimidine-2-thiolate) with Ru3(CO)12 at 55-60 °C also gives 2 in 38% yield. Both 1 and 2 have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction analysis.  相似文献   

17.
We measured nitrous oxide (N2O), dinitrogen (N2), methane (CH4), and carbon dioxide (CO2) fluxes in horizontal and vertical flow constructed wetlands (CW) and in a riparian alder stand in southern Estonia using the closed chamber method in the period from October 2001 to November 2003. The replicates’ average values of N2O, N2, CH4 and CO2 fluxes from the riparian gray alder stand varied from −0.4 to 58 μg N2O-N m−2 h−1, 0.02–17.4 mg N2-N m−2 h−1, 0.1–265 μg CH4-C m−2 h−1 and 55–61 mg CO2-C m−2 h−1, respectively. In horizontal subsurface flow (HSSF) beds of CWs, the average N2 emission varied from 0.17 to 130 and from 0.33 to 119 mg N2-N m−2 h−1 in the vertical subsurface flow (VSSF) beds. The average N2O-N emission from the microsites above the inflow pipes of the HSSF CWs was 6.4–31 μg N2O-N m−2 h−1, whereas the outflow microsites emitted 2.4–8 μg N2O-N m−2 h−1. In VSSF beds, the same value was 35.6–44.7 μg N2O-N m−2 h−1. The average CH4 emission from the inflow and outflow microsites in the HSSF CWs differed significantly, ranging from 640 to 9715 and from 30 to 770 μg CH4-C m−2 h−1, respectively. The average CO2 emission was somewhat higher in VSSF beds (140–291 mg CO2-C m−2 h−1) and at the inflow microsites of HSSF beds (61–140 mg CO2-C m−2 h−1). The global warming potential (GWP) from N2O and CH4 was comparatively high in both types of CWs (4.8 ± 9.8 and 6.8 ± 16.2 t CO2 eq ha−1 a−1 in the HSSF CW 6.5 ± 13.0 and 5.3 ± 24.7 t CO2 eq ha−1 a−1 in the hybrid CW, respectively). The GWP of the riparian alder forest from both N2O and CH4 was relatively low (0.4 ± 1.0 and 0.1 ± 0.30 t CO2 eq ha−1 a−1, respectively), whereas the CO2-C flux was remarkable (3.5 ± 3.7 t ha−1 a−1). The global influence of CWs is not significant. Even if all global domestic wastewater were treated by wetlands, their share of the trace gas emission budget would be less than 1%.  相似文献   

18.
A synthetic and mechanistic study is reported on ligand substitution and other reactions of six-coordinate ruthenium(II) carbonyl complexes containing tridentate PhP(CH2CH2CH2PCy2)2 (Cyttp). Carbonylation of cis-mer-Ru(OSO2CF3)2(CO)(Cyttp) (1) affords [cis-mer-Ru(OSO2CF3)(CO)2(Cyttp)]O3SCF3 (2(O3SCF3)) and, on longer reaction times, [cis-mer-Ru(solvent)(CO)2(Cyttp)](O3SCF3)2 (solvent = acetone, THF, methanol). 2(O3SCF3) reacts with each of NaF, LiCl, LiBr, NaI, and LiHBEt3 to yield [cis-mer-RuX(CO)2(Cyttp)]+ (X = F (3), Cl (4), Br (5), I (6), H (7)), isolated as 3-7(BPh4). These conversions proceed with high stereospecificity to afford only a single isomer of the product that is assigned a structure in which the Ph group of Cyttp points toward the CO trans to X (anti when X = F, Cl, Br, or I; syn when X = H). Treatment of 2(O3SCF3) with NaOMe and CO generates the methoxycarbonyl complex [cis-mer-Ru(CO2Me)(CO)2(Cyttp)]+ (8), whereas addition of excess n-BuLi to 2(O3SCF3) in THF under CO affords mer-Ru(CO)2(Cyttp) (9). The two 13C isotopomers [cis-mer-Ru(OSO2CF3)(CO)(13CO)(Cyttp)]O3SCF3 (2′(O3SCF3): 13CO trans to PC; 2″(O3SCF3): 13CO cis to all P donors) were synthesized by appropriate adaptations of known transformations and used in mechanistic studies of reactions with each of LiHBEt3, NaOMe/CO, and n-BuLi. Whereas LiHBEt3 reacts with 2′(O3SCF3) and 2″(O3SCF3) to replace triflate by hydride without any scrambling of the carbonyl ligands, the corresponding reactions of NaOMe-CO are more complex. The methoxide combines with the CO cis to triflate in 2, and the resultant methoxycarbonyl ligand ends up positioned trans to the incoming CO in 8. A mechanism is proposed for this transformation. Finally, treatment of either 2′(O3SCF3) or 2″(O3SCF3) with an excess of n-BuLi leads to the formation of the same two ruthenium(0) isomers of mer-Ru(CO)(13CO)(Cyttp). These products represent, to our knowledge, the first example of a syn-anti pair of isomers of a five-coordinate metal complex.  相似文献   

19.
Adding one equivalent of H2O2 to compounds of stoichiometry MoCl2(O)2(OPR3)2, OPR3 = OPMePh2 or OPPh3, leads to the formation of oxo-peroxo compounds MoCl2(O)(O2)(OPR3)2. The compound MoCl2(O)(O2)(OPMePh2)2 crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl2(O)(O2)(OPPh3)2, was not isolated in pure form, co-crystallized with MoCl2(O)2(OPPh3)2 in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on 18O isotopic studies and involves exchange between the alcohol and metal bonded O atoms.  相似文献   

20.
The bis(2-methoxyethyl)dithiocarbamate complexes [M{S2CN(CH2CH2OMe)2}2] (M = Ni, Cu, Zn, Pd) are readily prepared and the three lighter complexes have been crystallographically characterised. Disproportionation of [Cu{S2CN(CH2CH2OMe)2}2] upon addition of Cu(ClO4)2 · 6H2O affords the copper(III) complex [Cu{S2CN(CH2CH2OMe)2}2][ClO4] which has also been crystallographically characterised. Unlike other copper(III) dithiocarbamate salts, there are no intermolecular cation-cation or cation-anion interactions.  相似文献   

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